Many studies have shown that subjects exposed to misleading suggestions after witnessing an event are likely to incorporate the suggested information into their reports of the event. Although numerous studies have documented these suggestibility effects, little is known about the extent to which people come to believe they actually remember seeing the items that were merely suggested to them. Recent studies conducted in our laboratory suggest that subjects do, under some conditions, come to believe they remember seeing the suggested items they report, an error we refer to as a source misattribution error. Nevertheless, it is also clear that source misattribution is not an inevitable consequence of exposure to suggestion. The goal of the proposed work is to develop a model that will specify when source monitoring following exposure to suggestion will be accurate and when it is likely to fail. The proposed studies have three specific aims designed to achieve this objective. The first aim is to evaluate and identify the specific memory characteristics that facilitate and hinder accurate source monitoring performance. Several studies will evaluate the role of characteristics such as contextual cues, visual/spatial detail, and semantic elaboration in source monitoring performance. A second aim is to examine how source misattributions vary as a function of the number of exposures to the suggested item, the contextual variability of the repeated exposures, and the credibility of the source of the suggested information. The third aim is to extend the study of source misattributions following exposure to suggestion by (a) examining the role of conscious recollection in source misattributions, (b) exploring the effects of implied rather than explicit suggestion and (c) assessing age-related changes in the propensity toward source misattribution errors. Collectively, the results of the proposed studies should lay the empirical groundwork for the development of a theory on the role of source monitoring in suggestibility. In addition, to the extent that some forms of amnesia and age-related dementia are characterized by failures in source monitoring, the proposed work has implications for understanding memory dysfunction.